Processing of flexible substrates, such as plastic films or foils, is in high demand in the packaging industry, semiconductor industries and other industries. Processing may consist of coating of a flexible substrate with a desired material, such as a metal, in particular aluminum, semiconductor and dielectric materials, of etching and of other processing steps conducted on a substrate for the desired applications. Systems performing this task generally include a processing drum, e.g., a cylindrical roller, coupled to a processing system for transporting the substrate, and on which at least a portion of the substrate is processed. Further roller devices may help to guide and direct the substrate to be coated in the deposition chamber.
Generally, an evaporation process, for instance a thermal evaporation process, can be utilized for depositing thin layers of metals which can be metallized onto flexible substrates. Roll-to-Roll deposition systems are also experiencing a strong increase in demand in the display industry and the photovoltaic (PV) industry. For example, touch panel elements, flexible displays, and flexible PV modules result in an increasing demand for depositing suitable layers in Roll-to-Roll coaters, particularly with low manufacturing costs.
Flexible substrates can be processes with a plurality of processes, such as PVD, CVD, such as PECVD, etching, thermal processing or the like. Particularly for manufacturing more sophisticated electronics, optoelectronics or other devices, contacting of the surface, which is to be processed or has been processed needs to be avoided. Yet further, the requirements of the processing, e.g. deposition, show increasing demands with respect to uniformity, precision and the like, particularly for thin films. Thereby, the substrate needs to transported and wound wrinkle-free.
In view of the above, it is an object of the present invention to provide a vacuum deposition apparatus for a flexible substrate and a method for operating a vacuum deposition apparatus that overcomes at least some of the problems in the art.